By Dr. Greg Nowacki, R09 Regional Ecologist, U.S. Forest Service
November 20, 2018 at 1:00 PM central
This presentation will describe the relations between historic fire and the development of pine-oak ecosystems. The effective removal of fire through 20th Century fire suppression efforts has had devastating ecological effects on pine-oak ecosystems throughout the eastern United States. The removal of landscape-level burning has led to cascade of changes, converting once open woodlands to closed-canopy forests, ensuing understory shading, and the loss of light-demanding grasses, herbs, and shrubs. Current conditions are so dire that oak and pine can no longer effectively regenerate and recruit, whereas shade-tolerant, fire-sensitive species, such as maple and beech, proliferate. As systems shift toward shade-tolerant competitors, understories become progressively more shaded, cooler and moister, and fuel beds less receptive to fire -- a phenomenon referred to as “mesophication.” A regiment of thinning and burning is recommended to restore conditions favorable to oak and pine regeneration and overall ecosystem restoration. To counteract the current negative ecological trends on former pyrogenic landscapes, the units of the Eastern Region have been increasing their burn acreage over an 11-yr period. The Region collectively burns about 60,000 acres each year. However, when compared to the historic burning regime, this acreage represents only a small fraction (6%) of what burned in the past. The presentation concludes with discussing barriers to prescribed burning.